Here during partial ordering of the two partial specializations we end up in unify with parm=arg=NONTYPE_ARGUMENT_PACK<V0, V1>, and crash shortly thereafter because uses_template_parms calls potential_constant_expression which doesn't handle NONTYPE_ARGUMENT_PACK.
This patch fixes this by checking dependent_template_arg_p instead of uses_template_parms when parm==arg, which does handle NONTYPE_ARGUMENT_PACK. We could also perhaps fix uses_template_parms / inst_dep_expr_p to better handle NONTYPE_ARGUMENT_PACK, but interestingly none of our existing tests exercise calling those functions on NONTYPE_ARGUMENT_PACK, so such a fix would be seemingly moot. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk/11? PR c++/102547 gcc/cp/ChangeLog: * pt.c (unify): Check dependent_template_arg_p instead of uses_template_parms when parm==arg. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/variadic-partial2.C: New test. --- gcc/cp/pt.c | 2 +- .../g++.dg/cpp0x/variadic-partial2.C | 16 ++++++++++++++ .../g++.dg/cpp0x/variadic-partial2a.C | 22 +++++++++++++++++++ 3 files changed, 39 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C create mode 100644 gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 1dcdffe322a..59c00c77a30 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -23587,7 +23587,7 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict, even if ARG == PARM, since we won't record unifications for the template parameters. We might need them if we're trying to figure out which of two things is more specialized. */ - if (arg == parm && !uses_template_parms (parm)) + if (arg == parm && !dependent_template_arg_p (parm)) return unify_success (explain_p); /* Handle init lists early, so the rest of the function can assume diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C new file mode 100644 index 00000000000..df61f26a3c1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2.C @@ -0,0 +1,16 @@ +// PR c++/102547 +// { dg-do compile { target c++11 } } + +template<int... Vs> +struct vals { }; + +template<class V, class T> +struct vals_client { }; + +template<int V0, int V1, class T> +struct vals_client<vals<V0, V1>, T> { }; + +template<int V0, int V1> +struct vals_client<vals<V0, V1>, void> { }; + +template struct vals_client<vals<1, 2>, void>; //- "sorry, unimplemented..., ICE" diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C new file mode 100644 index 00000000000..cc0ea488ad3 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/variadic-partial2a.C @@ -0,0 +1,22 @@ +// PR c++/102547 +// { dg-do compile { target c++11 } } +// A version of variadic-partial2.C where the partial ordering is performed +// on function templates instead of class templates. + +template<int... Vs> +struct vals { }; + +template<class V, class T> +void f(V, T) { }; + +template<int V0, int V1, class T> +void f(vals<V0, V1>, T) { }; + +template<int V0, int V1> +void f(vals<V0, V1>, char) { }; + +template void f(vals<1, 2>, char); //- "sorry, unimplemented..., ICE" + +int main() { + f(vals<1, 3>{}, 'a'); //- "sorry, unimplemented..., ICE" +} -- 2.33.0.610.gcefe983a32